Sir Graham Hearne has been appointed chairman of Catlin Westgen Group, the parent of Catlin Underwriting Agencies at Lloyd's of London.
Sir Graham will serve as a non-executive chairman.
Group chief executive Stephen Catlin said: "I am delighted that Sir Graham has agreed to join the Catlin Group as chairman of CWGL.
"With his combination of experience in international business, finance, government and law, Sir Graham is the perfect person to lead our rapidly expanding group and to help us become a leader in the global insurance industry."